Metformin: Environmental fate and effects on the fathead minnow (Pimephales promelas)

This study aimed to address the toxicological effects the type-2 diabetes drug, metformin has on wild fathead minnows (Pimephales promelas). Fathead minnow embryos and adults were exposed to metformin via in-lake mesocosm and their survival, development and growth was assessed. Exposures were conducted at Lake 114 located at the International Institute for Sustainable Development-Experimental Lakes Area (IILSD-ELA) in northern Ontario, Canada. Adults were exposed for 56 days to three concentrations of metformin (0, 4, and 40 micrograms per liter (ug/L)) each with four replicates. Fish behavior and mortality was observed daily during the exposure period. After 56 days, fish were captured, dissected and assessed for various health endpoints. Additionally, blood, brain and tissue samples were collected for metabolic endpoints. Additionally, wild fathead minnow eggs spawned in the lake were collected in glass mason jars and transported back to the on site laboratory. One fertilized egg was placed in each well for a total of 20 eggs per plate (thus 20 eggs per replicate for the 3 replicates for a total of 60 eggs per mesocosm and a total of 240 eggs per treatment). Hatching time, measurements, survival and deformities were observed.

Supplemental Information

Supporting projects: Chemicals Management Plan (CMP)

The Chemicals Management Plan (CMP) is a Government of Canada initiative aimed at reducing the risks posed by chemicals to Canadians and their environment. A key element of the Chemicals Management Plan is the monitoring and surveillance of levels of harmful chemicals in Canadians and their environment. Monitoring and surveillance are essential to identify and track exposure to hazards in the environment and associated health implications. Monitoring and surveillance programs provide the basis for making sound and effective public health and environmental health policies and interventions, as well as measuring the efficacy of control measures.

In support of the Chemicals Management Plan, monitoring and surveillance initiatives were established to support Health Canada and Environment and Climate Change Canada scientists, in collaboration with external partners and researchers, to advance our knowledge. This initiative has allowed the Government of Canada to increase its commitment to a number of existing monitoring initiatives, as well as to support new efforts.

For more information on the Chemicals Management Plan, please visit: https://www.canada.ca/en/health-canada/services/chemical-substances/chemicals-management-plan.html